The present invention relates to attaching computer terminals to a data transmission network. More specifically, the present invention is related to setting the attachment parameters of attached computer terminals and updating the settings when a computer terminal has become reattached to a network after having been removed from the network, either at the same location or at a different location, and in maintaining information as to the connection between the network and its terminals at both the terminals and the network.
Computer terminals for putting computing power on the desktop of a variety of users are well known in the art, as is connecting these computer terminals to a data transmission network to allow data and programs from other computers connected to the network to the network to be available to the user of an individual computer terminal.
One form of computer terminal that has been quite effective in connecting to a data transmission network for exchange of data and programs is the personal computer, particularly the IBM-brand personal computers. The personal computer typically includes a system unit with a single systems processor and memory, a display, at least one input/output device like a floppy disk drive, a hard drive or a printer/plotter. The personal computer advantageously includes means for attaching the personal computer systems processor to a data transmission network, a connection that may be made through any of a number of conventional physical and logical devices that are well known in the prior art such as a local area network, a token ring, or similar attachment mechanism.
The LAN Leash Patent discloses a system which monitors the continuity of connection between a personal computer and a data transmission network. When that connection is broken, even temporarily and even when the computer is not in a normal operating mode, a record is made of the break in connection and a network administrator is advised of the situation. The LAN Leash Patent discloses that the removal of a computer system from its connection to the data transmission network may be a cause for concern that a theft of the computer system may be in process, a growing concern since personal computers are becoming smaller and lighter, hence more easily transportable.
As the personal computer systems become more easily transportable and removable from the network, it becomes easier to relocate a personal computer from one place to another, either because the individual has changed offices or because the work has changed and the personal computer is moved to serve a new individual. A respected consulting organization which compiles and publishes information related to the computer industry has estimated that the typical personal computer attached to a data transmission network in a corporate environment will be moved three to five times during its useful life and that, using current procedures, each such move of a personal computer will cost the corporation an average of $200. Much of the cost of a move results from the labor to reconfigure the personal computer for its new attachment to the data transmission network. In some companies, with reorganizations, mission changes and other physical moves of employees, one out of two employees is moved each year.
This reconfiguration is typically accomplished by having a network specialist who knows the appropriate settings (addresses stored or set into the personal computer for use in attaching to the data transmission network) and the network configuration or how to find the settings and the network configurations so that a personal computer can be coupled to the network in its new location and with the appropriate settings.
The disconnection from (and reconnection to) the network may occur because the personal computer is being moved from one office to another or because the personal computer is being serviced. A connection to the network may also be broken if the computer is being removed, either with or without the owner""s consent or knowledge. Some personal computers are mobile by design, as in the case of a laptop personal computer like the IBM ThinkPad personal computers, and the user frequently removes such computers from the network for traveling to a different work location with his personal computer. Even if a laptop computer is not being taken away from the premises on which a data transmission network exists, the laptop computer may be removed from the network when the user is away from the office in order to secure the laptop personal computer from being taken by others.
Once the personal computer has been removed from the data transmission network, it may be reattached to the network in the same place (as in a worker who removes his laptop computer from his office to take it to a field location or home, then returns the laptop computer to his same office), in a similar place (like in an adjacent office or down the hall) or in a completely different location. Some of the data transmission networks have a very wide geographic range, some extending to different parts of a single town, some extending across states and some data transmission networks may even be worldwide. The connections to such networks may vary from having one only a few servers to being international with hundreds or thousands of servers.
One setting for attaching a personal computer or other terminal to a data transmission network such as an Internet or Internet is an Internet Protocol (IP) address. This may be a fixed address or setting (set once for the duration of the attachment of a particular computer terminal to the network) or it may be a dynamic setting (an new address or setting which is acquired each time the personal computer is attached to the network). IBM offers a program product called Dynamic Host Connection Program (DHCP) to allow a personal computer to get a new IP address each time the personal computer issues a request of the network, an activity which can be programmed to happen each time the computer is turned on while attached to the network or each time the computer is attached to the Internet or the intranet. This program is simple, in concept, in that the personal computer or terminal sends a request to the data transmission network for a new IP address, and it receives from the network an IP address. Obviously, the system providing the IP addresses must know which IP addresses it has used (to avoid duplication) and which ones remain available for assignment. It would be desirable if the assignment of IP addresses knew which IP addresses were no longer in use so they could be reused (or the supply of IP addresses would be exhausted after a period of time).
In addition to setting the Internet Protocol (which is the address by which the network knows the terminal), the terminal requires that certain fields be set up for its usexe2x80x94fields like its xe2x80x9cname serverxe2x80x9d and other values that are stored and referred to as xe2x80x9csettingsxe2x80x9d. Again, a network specialist who assists with the move of a personal computer can physically attend to changing the terminal settings when a personal computer or terminal has been moved from one location to another, but this is an expensive and time-consuming process.
Moving a computer terminal attached to a data transmission network typically required that the user coordinate with a network specialist to come to his new location to provide the new settings. This either requires an amount of advance coordination (to schedule the move when the network specialist is available) or waiting until the network specialist can provide his services. Since many corporate moves involve multiple office changes relatively simultaneously (when a first and second worker exchange offices, they both require service at the same time, and some moves of workers with their computer terminals involve hundreds of workers).
Accordingly, the practice of removing personal computers from the data transmission networks for whatever reason and then reattaching the personal computers to the data transmission network, sometimes in the same place, and other times in a new location, raises the question of whether the old settings will be effective for the computer to attach to the data transmission network and whether it will require a personal visit from a network specialist.
Other disadvantages and limitations of the prior art systems for attaching computer terminals to computer networks will be apparent to those skilled in the art of communication between computer terminals and computer networks in view of the detailed description of the preferred embodiment of the present invention taken together with the accompanying drawings and the appended claims.
The present invention overcomes the disadvantages of the prior art by providing a system for attaching computer terminals to a data transmission network which is simple and inexpensive without using unnecessary resources but which provides the correct settings for connection of the computer terminal to the data transmission network.
The present invention does not require the presence of a network specialist to reset the settings of computer terminals which have been moved to new locations on a data transmission network. This avoids the delays which would otherwise occur if the user could not start using his computer terminal in a new location until the network specialist came to his location to store the appropriate parameters in the computer terminal for the new location on the data transmission network.
A system for obtaining an Internet Protocol address for a terminal is known in the art. A computer program which generates such an IP address suitable for a terminal is the Host Data Control Program (HDCP). This provides an Internet Protocol address for a terminal in response to a request coming from that terminal.
In addition to an IP address the terminal needs to know its serverxe2x80x94what computer in the network it will address with its requests, and which computer will be receiving its information for transmission to the terminal. Typically, a server serves a small number of terminals, and each network has a plurality of servers, and the server maintains address informationxe2x80x94what computers are attached and wherexe2x80x94so that information packets from the data transmission network may be properly distributed to the terminals as they arrive.
The present invention has the advantage that it seeks an Internet Protocol (IP) address when it needs one because the terminal has been moved, but it does not seek a new IP address when the computer terminal does not require a new IP address, as when the computer terminal has been reconnected in the same place or when the previous settings will continue to be effective for the new location.
By avoiding seeking an unnecessary new IP address, the system avoids adding an unnecessary load on the data transmission network. Since many users would turn on their terminals at about the same time (for example, at the beginning of a work day), if each user was requesting a new IP address at about the same time, the network could spend a lot of resources (use a lot of its capacity) in receiving and filling unnecessary requests for new IP addresses. Many computer terminals are not moved since the last use of the terminal, so therefore the IP addresses stored in the terminal would be usable without a change or without even contacting the network on the matter of the IP address.
The present invention, being a system in which new settings are provided through the network when needed, also mean that fewer network specialists will be needed to support the moving or computer terminals, avoiding the cost of such individuals and allowing them to spend their time more productively.
Other objects and advantages will be apparent to those skilled in the art in view of the description of he preferred embodiment and the appended claims and the accompanying drawings.